Persistent Binding Overview

The /dev/rmt directory contains links to physical devices under /devices for tape devices.
Each tape LUN seen by the system is represented by 24 minor nodes
in the form of /dev/rmt/N, /dev/rmt/Nb, and /dev/rmt/Nbn, where N is an integer
counter starting from 0. This number is picked by devfsadm during enumeration of
new devices. Every new tape logical unit number (LUN) found by devfsadm gets
the next available number in /dev/rmt.

Because the /dev/rmt name depends on the order in which devices appear in
the device tree, it changes from system to system. For a given tape
drive that is seen by two or more different systems, the /dev/rmt
link can be different on each of these systems. This difference can cause
problems for the most common usage of Symantec (VERITAS) NetBackup (SSO option). Also,
if the drive is replaced, the links change unless the vendor provides a
way to retain the port World-Wide Name (PWWN) of the drive.